Many applications for proteins such as lactoferrin and lactoperoxydase are known, particularly in the alimentary field and therapeutics.
As a result of an ever-increasing demand for such proteins, there is a need for a single process which can be applied to extract various proteins from various media. Such a process is not presently available.
For example, French Pat. No. 2,505,615 teaches a process for extracting two individual proteins from milk, but this process specifically requires modification of the pH of the milk to be treated. Furthermore, the process described in the patent utilizes powders of inorganic absorbents, such as silica, in the form of macroporous and microscopic beads. This makes it necessary to work in a medium which is free from casein and lipids in order to avoid rapid blocking of the resin.
Processes have also been proposed which utilize ion exchange resins in particles which are less fine than the inorganic powder beads. However, due to their macroporous structure, these resins also have the disadvantage of being rapidly blocked.
The use of titanium oxide beads, the diameter of which can vary between 50 microns and several centimeters, as an absorbing material has also been proposed. However, a material of this type requires the milk and/or the milk whey to be pretreated in order to reduce the ion concentration therein. Otherwise, the proteins cannot be recovered. This pretreatment consequently represents additional operations and a modification of the medium.
Thus, there is a need for a process which can readily extract proteins from a medium as complex as whole milk, which comprises fats, lipid globules and casein micelles, wherein the process is free of the above mentioned disadvantages of blocking, or requiring the medium to be pretreated.